1. Field of the Invention
The present invention relates generally to product transfer systems. More particularly, embodiments of the present invention relate to product transfer systems and devices configured to effectively and efficiently manage product transfer operations and to minimize the escape of product after a product transfer operation has been completed.
2. Related Technology
Many industries and industrial processes require that liquid products such as chemicals, solvents and process intermediates, as well as various non-liquid particulate or pelletized materials, be transferred to, and/or between, containers such as railcars, road tankers, intermediate bulk containers, as well as containers located on ships and other vessels. Such containers are configured in a variety of different ways and may include one or more top, bottom and/or side loading openings configured and arranged to interface with a product transfer device so that product can be introduced into and/or removed, or educted, from the container by way of the product transfer device.
Typically, such product transfer devices comprise one or more hoses supported by a loading arm. A rigid tube disposed at a terminal end of the hose is configured to direct the flow of product to the container, or may be inserted into the opening of the container as necessary to remove product from the container.
However, the wide variety of containers that may be required to be filled or emptied makes the use of such devices problematic. In particular, it is often the case that considerable maneuvering of the loading arm, and hose, is necessary in order to properly position the hose and rigid tube relative to the container in preparation for a product transfer operation. Thus, the loading arms typically employed in connection with many product transfer devices are constructed in a mechanically complex fashion so that such loading arms are better able to meet a variety of operational conditions. Unfortunately, such complex construction makes the loading arms prone to operational and other problems that affect the reliability and utility of the loading arm.
A related problem concerns certain operational requirements of many loading arm assemblies. In particular, while containers that are involved in transfer operations, such as a rail car for example, may in some instances be precisely positioned, the configuration of the loading arm is such that a substantial amount of overhead space must be available so as to enable the hose and loading arm to be readily moved into, and out of, position relative to the container.
Yet other problems with many loading arms and related systems concern the relative lack of precision with which they can be maneuvered. Specifically, while such arms may be maneuvered to a variety of positions, it is often the case that considerable physical effort is required on the part of operating personnel in order to precisely position the arm and hose in preparation for a product transfer operation. As a result, harm to personnel and/or damage to property may occur as the hose and loading arm is moved into, and out of, position.
In addition to being relatively difficult to maneuver and position, many product transfer devices, such as loading arm and hose systems, are of limited effectiveness where product control is concerned. In this regard, the use of such product transfer devices generally involves positioning the hose and rigid tube near the opening of the container. The product is then deposited into the container, or educted from the container, as applicable, via the rigid tube.
Subsequent to the transfer operation, the rigid tube is retracted from the container and moved to a stored position. During the retraction and storage processes however, any spray or other residue present on the outside of the tube and/or hose often runs down the outside of the tank, vessel or other container. This problem is particularly acute where the tube and/or hose is relatively long. As a result of the presence of these materials on containers and other structures, operating personnel must take great care in order to avoid slipping and injuring themselves. Nonetheless, injuries often occur as a result of the presence of such slick conditions.
The presence of such spray and/or residue is problematic for other reasons as well. In particular, where hazardous materials are being transferred, the presence of these materials on the outside of the container can pose a hazard to operating personnel, as well as to the environment. In addition, any material remaining on the loading arm and/or hose after a transfer operation can damage the arm and hose, and may also contaminate other materials with which the hose and/or arm come into contact.
Moreover, the presence of product within the tube and hose, after the transfer process has been completed, is problematic as well. For example, some loading arm assemblies include hoses, tubes and other product transfer elements that are configured such that even after product transfer is completed, and the shutoff valve is closed, product remaining in the lower portion of the tube or hose is still able to escape and run onto the container and/or other structures as the tube is retracted and stored. As noted earlier herein, such an escape of the product presents a hazard both to operating personnel and to the environment.
In view of the foregoing, and other, problems in the art, what is needed is a product transfer device that includes features directed to minimizing the escape of product subsequent to completion of a product transfer operation. Additionally, the product transfer device should be relatively easy to position and operate.